Amorphous MnO2 modulates the electrochemical performance of Si@AMOA lithium-ion battery anode materials

Silicon (Si) exhibits significant potential as a high-capacity anode material for lithium-ion batteries. However, its commercial viability is hindered by challenges such as volumetric expansion during charge and discharge cycles, inadequate electrical conductivity, and a limited cycle life. To address these issues, the combination of Si with transition metal oxides and carbon coatings has proven to be an effective strategy for enhancing cycling performance. This paper presents a straightforward and cost-effective one-pot method for synthesizing Si@AMOA (Silicon composite carbon-coated amorphous manganese oxides) composites. The pores between the cross-linked nanorods can provide a large volume expansion space, and the embedded nanorods have strong Si C bonding, which can buffer the volume change of the Si active material, while the use of phenolic resin to form an amorphous carbon layer encapsulated with Si-composite amorphous MnO 2 improves electrical conductivity and stability, and the Si@AMOA anode material is loose and porous, with a large specific surface area, which is conducive to the ionic and electronic transport. The absence of the MnO 2 lattice leads to the presence of oxygen vacancies thus enabling the electrode material to have a better wettability with the electrolyte, which reduces the polarisation and improves the material's electrical conductivity, thus enabling the lithium to be rapidly intercalated/decalcified through the thin wall, thus improving its cycling stability performance. The Si@AMOA anode demonstrates a specific discharge capacity of 972.6 mAh g −1 after more than 600 cycles at a current density of 0.5 A g −1 , while exhibiting excellent electrochemical stability across varying current densities.